Nitrothiophenes, fungicidal and/or bactericidal compositions containing nitrothiophenes, and use thereof

ABSTRACT

The invention relates to new nitrothiophenes of the general formula ##STR1## wherein R is an alkyl group having 1 to 12 carbon atoms, which alkyl group may be substituted with a phenyl group substituted, if desired, with nitro, halogen, alkyl with 1 to 4 carbon atoms or alkoxy with 1 to 4 carbon atoms, with an alkoxycarbonyl group having 2 to 5 carbon atoms, or with a thiocyanato group, or 
     R is a phenyl group, a pyridyl group or an N-oxypyridyl group, which groups may be substituted with nitro, halogen, alkyl with 1 to 4 carbon atoms, or alkoxy with 1 to 4 carbon atoms; 
     R 1  is a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group substituted or not substituted with nitro, halogen, alkyl with 1 to 4 carbon atoms, or alkoxy with 1 to 4 carbon atoms; 
     R 2  is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a cyano group, an alkanoyl group having 1 to 5 carbon atoms, an α,α-dialkoxyalkyl- or α,α-alkylene-dioxyalkyl group having 3 to 10 carbon atoms, a carboxy group, an alkoxycarbonyl group having 2 to 5 carbon atoms, an α-hydroxyalkyl group having 1 to 4 carbon atoms, an α-haloalkyl group having 1 to 4 carbon atoms, an α-alkoxyalkyl group having 2 to 6 carbon atoms, an alkoxycarboximidoyl group having 2 to 5 carbon atoms, a sulpho group, an amino-, alkylamino- or dialkylamino- sulphonyl group, the alkyl group(s) of which has (have) 1 to 4 carbon atoms, or an alkoxysulphonyl group having 1 to 4 carbon atoms, and 
     n is 0 to 2. 
     The compositions are particularly suitable to prevent infections by phytophagous microorganisms in agriculture and horticulture. For this purpose, the seed is treated prior to sowing or the soil destined for sowing or planting is treated with the composition in a dosage from 100 to 1,500 mg of active substance per kg of seed and from 2 to 100 kg of active substance per hectare, respectively.

REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of copending application Ser.No. 217,172 filed Dec. 16, 1980 now abandoned.

BACKGROUND OF THE INVENTION

The invention relates to new nitrothiophenes and fungicidal and/orbactericidal compositions, particularly compositions for the treatmentof soil or seed against phytophagous microoganisms, which compositionscontain the new nitrothiophenes as active substances, and to the use ofthese compositions in agriculture and horticulture.

DISCUSSION OF THE PRIOR ART

German Offenlegungsschrift No. 2,627,328 discloses nitrothiazoles withfungicidal activity, for example, for the treatment of seeds. A compounddescribed in this application is2-methylsulphinyl-4-methyl-5-nitro-thiazole.

GENERAL DESCRIPTION OF THE INVENTION

The present invention relates to new compounds of the general formula##STR2## wherein R is an alkyl group having 1 to 12 carbon atoms, whichalkyl group may be substituted with a phenyl group substituted, ifdesired, with nitro, halogen, alkyl with 1 to 4 carbon atoms or alkoxywith 1 to 4 carbon atoms, with an alkoxycarbonyl group having 2 to 5carbon atoms, or with a thiocyanato group, or

R is a phenyl group, a pyridyl group or an N-oxypyridyl group, whichgroups may be substituted with nitro, halogen, alkyl with 1 to 4 carbonatoms, or alkoxy with 1 to 4 carbon atoms;

R₁ is a hydrogen atom, a halogen atom, an alkyl group having 1 to 4carbon atoms, or a phenyl group optionally substituted with nitro,halogen, alkyl with 1 to 4 carbon atoms, or alkoxy with 1 to 4 carbonatoms;

R₂ is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, acyano group, an alkanoyl group having 1 to 5 carbon atoms, anα,α-dialkoxyalkyl- or α,α-alkylenedioxyalkyl group having 3 to 10 carbonatoms, a carboxy group, an alkoxycarbonyl group having 2 to 5 carbonatoms, an α-hydroxyalkyl group having 1 to 4 carbon atoms, anα-haloalkyl group having 1 to 4 carbon atoms, an α-alkoxyalkyl grouphaving 2 to 6 carbon atoms, an alkoxycarboximidoyl group having 2 to 5carbon atoms, a sulpho group, an amino-, alkylamino- ordialkylaminosulphonyl group, the alkyl group(s) of which has (have) 1 to4 carbon atoms, or an alkoxysulphonyl group having 1 to 4 carbon atoms,and

n is 0 to 2.

Of these new compounds, those which have been shown to have excellentsuitability as fungicides and/or bactericides, are compounds of thegeneral formula ##STR3## wherein R' is an alkyl group with 1 to 4 carbonatoms,

m is 0 or 1, and, if m is 0,

R₁ ' and R₂ ' are both hydrogen atoms, and, if m is 1,

R₁ ' is a hydrogen atom or an alkyl group with 1 to 4 carbon atoms andR₂ ' is a hydrogen atom or an acetyl group.

Examples of new nitrothiophenes according to the present invention thathave a high fungicidal and/or bactericidal activity are:

(1) 2-methylsulphinyl-3-nitrothiophene,

(2) 2-methylsulphinyl-3-nitro-4-methylthiophene,

(3) 2-ethylsulphinyl-3-nitrothiophene,

(4) 2-n-propylsulphinyl-3-nitrothiophene,

(5) 2-isobutylsulphinyl-3-nitrothiophene,

(6) 2-ethylthio-3-nitrothiophene, and

(7) 2-methylsulphinyl-3-nitro-5-acetylthiophene.

Examples of other new nitrothiophenes according to the present inventionthat have a fungicidal and/or bactericidal activity are:

(8) 2-methylsulphinyl-3-nitro-5-ethoxycarbonylthiophene,

(9) 2-methylsulphinyl-3-nitro-5-ethoxycarboximidoylthiophene,

(10) 2-methylsulphinyl-3-nitro-5-cyanothiophene,

(11) 2-methylsulphonyl-3-nitrothiophene,

(12) 2-methylsulphonyl-3-nitro-4-methylthiophene,

(13) 2-methylsulphinyl-3-nitro-4,5-dimethylthiophene,

(14) 2-phenylsulphinyl-3-nitrothiophene,

(15) 2-[3-nitrothienyl(-2)sulphinyl]pyridine-N-oxide,

(16) 2-(4-methoxyphenylsulphinyl)-3-nitrothiophene,

(17) 2-(4-chlorophenylsulphinyl)-3-nitrothiophene,

(18) 2-(4-nitrophenylsulphinyl)-3-nitrothiophene,

(19) 2-methylsulphinyl-3-nitro-4-phenylthiophene,

(20) 2-methylsulphonyl-3-nitro-4-phenylthiophene,

(21) 2-ethylsulphonyl-3-nitrothiophene,

(22) 2-n-propylsulphonyl-3-nitrothiophene,

(23) 2-n-heptylsulphinyl-3-nitrothiophene,

(24) 2-methylsulphonyl-3-nitro-5-cyanothiophene,

(25) 2-ethoxycarbonylmethylsulphonyl-3-nitrothiophene,

(26) 2-ethoxycarbonylmethylsulphinyl-3-nitrothiophene,

(27) 2-[3-nitro-5-cyanothienyl(-2)sulphinyl]pyridine-N-oxide,

(28) 2-phenylsulphinyl-3-nitro-5-cyanothiophene,

(29) 2-phenylsulphonyl-3-nitro-5-cyanothiophene,

(30) 2-[3-nitrothienyl(-2)sulphinyl]-3-nitropyridine,

(31) 2-methylsulphonyl-3-nitro-5-acetylthiophene,

(32) 2-methylsulphinyl-3-nitro-4-chlorothiophene,

(33) 2-thiocyanatomethylsulphonyl-3-nitrothiophene,

(34) 2-thiocyanatomethylsulphinyl-3-nitrothiophene,

(35) 2-thiocyanatomethylthio-3-nitrothiophene,

(36) 2-[3-nitro-5-formylthienyl(-2)thio]pyridine-N-oxide,

(37) 2-methylthio-3-nitro-4-methylthiophene,

(38) 2-methylsulphinyl-3-nitro-5-N,N-dimethylaminosulphonylthiophene,

(39) 2-methylsulphonyl-3-nitro-5-N,N-dimethylaminosulphonylthiophene,

(40) 2-ethylsulphinyl-3-nitro-5-acetylthiophene,

(41) 2-ethylsulphonyl-3-nitro-5-acetylthiophene,

(42) 2-methylsulphinyl-3-nitro-5-hydroxymethylthiophene,

(43) 2-methylsulphonyl-3-nitro-5-hydroxymethylthiophene,

(44) 2-methylsulphinyl-3-nitro-5-(1-hydroxyethyl)thiophene,

(45) 2-methylsulphonyl-3-nitro-5-(1-hydroxyethyl)thiophene,

(46) 2-methylsulphinyl-3-nitro-5-ethylenedioxymethylthiophene,

(47) 2-methylsulphonyl-3-nitro-5-ethylenedioxymethylthiophene, and

(48) 2-methylsulphinyl-3-nitro-5-bromomethylthiophene.

The new compounds according to the present invention show a strongfungicidal activity with respect to a wide spectrum of pathogenic fungiwhich may occur in agricultural and horticultural crops, for example,Phytophthora infestans on tomato, Sphaerotheca fuliginea on cucumber,Uromyces phaseoli on bean, and Pyricularia oryzae on rice.

It has been found that the new compounds according to the presentinvention are particularly active against phytophagous microorganisms,e.g., against phytophagous soil fungi ("soil-borne diseases"), forexample, Pythium spp. (for example, Pythium ultimum) and Rhizoctoniasolani, against phytophagous fungi which are transferred with the seed("seed-borne diseases"), for example, Pyrenophora graminea on barley,Tilletia caries on wheat, Fusarium spp. (for example, Fusarium nivale)on wheat and Ustilago spp. (for example, Ustilago avenae) on oats, andagainst phytophagous bacteria, for example, Erwinia carotovora.

The new compounds according to the present invention are considerablymore effective than 2-methylsulphinyl-4-methyl-5-nitrothiazole disclosedin the above-mentioned German Offenlegungsschrift, as will becomeapparent from the examples. Infections with phytophagous bacteria and/orfungi, e.g., phytophagous soil fungi or fungi which are transferred withthe seed, can be prevented by treating the soil destined for planting orsowing, or, which will usually be preferred for economical reasons, theseed itself with a composition which comprises a new compound accordingto the invention.

For practical applications, the substances in accordance with thepresent invention are processed to compositions. In such compositions,the active substance is mixed with solid carrier material or dissolvedor dispersed in liquid carrier material, and if desired, in combinationwith auxiliary substances, for example, emulsifiers, wetting agents,dispersion agents, and stabilizers.

Examples of compositions according to the present invention are aqueoussolutions and dispersions, oily solutions and oily dispersions,solutions in organic solvents, pastes, dusting powders, dispersingpowders, miscible oils, granules, pellets, invert emulsions, aerosolcompositions, and fumigating candles.

Dispersible powders, pastes, and miscible oils are compositions inconcentrate form which are diluted prior to or during use.

The invert emulsions and solutions in organic solvents are mainly usedfor application by air, namely when large areas are treated with acomparatively small quantity of composition. The invert emulsion can beprepared shortly before or even during spraying in the sprayingapparatus by emulsifying water in an oily solution or an oily dispersionof the active substance. The solutions of the active substance inorganic solvents may be provided with a phytotoxicity-reducingsubstance, for example, wool fat, wool fatty acid, or wool fattyalcohol.

A new form of composition will be described in greater detailhereinafter by way of example.

Granular compositions are prepared by taking up, for example, the activesubstance in a solvent or dispersing it in a diluent and impregnatingthe resulting solution/suspension, if desired, in the presence of abinder, on granular carrier material, for example, porous granules(e.g., pumice and attaclay), mineral non-porous granules (sand or groundmarlow), organic granules (e.g., dried coffee grounds, cut tobaccostems, and ground corncobs). A granular composition can also be preparedby compressing the active substance together with powdered minerals inthe presence of lubricants and binders and disintegrating the compressedproduct to the desired grain size and sieving it. Granular compositionscan be prepared in a different manner by mixing the active substance inpowder form with powdered fillers, and agglomerating the mixture then tothe desired particle size.

Dusting powders can be obtained by intimately mixing the activesubstance with an inert solid powdered carrier material, for example,talcum.

Dispersible powders are prepared by mixing 10 to 80 parts by weight of asolid inert carrier, for example, kaolin, dolomite, gypsum, chalk,bentonite, attapulgite, colloidal SiO₂ or mixtures of these and similarsubstances, with 10 to 80 parts by weight of the active substance, 1 to5 parts by weight of a dispersing agent, for example, the ligninsulphonates or alkylnaphthalene sulphonates known for this purpose,preferably also 0.5 to 5 parts by weight of a wetting agent, forexample, fatty alcohol sulphates, alkyl aryl sulphonates, fatty acidcondensation products, or polyoxyethylene compounds, and finally, ifdesired, other additives.

For the preparation of miscible oils, the active compound is dissolvedin a suitable solvent which preferably is poorly water-miscible, and oneor more emulsifiers are added to this solution. Suitable solvents are,for example, xylene, toluene, petroleum distillates which are rich inaromatics, for example, solvent naphtha, distilled tar oil, and mixturesof these liquids. As emulsifiers may be used, for example,polyoxyethylene compounds and/or alkyl aryl sulphonates. Theconcentration of the active compound in these miscible oils is notrestricted to narrow limits and may vary, for example, between 2 and 50%by weight.

In addition to a miscible oil may also be mentioned as a liquid andhighly concentrated primary composition a solution of the activesubstance in a readily water-miscible liquid, for example, a glycol orglycol ether, to which solution a dispersion agent and, if desired, asurface-active substance, has been added. When diluting with watershortly before or during spraying, an aqueous dispersion of the activesubstance is then obtained.

An aerosol composition according to the present invention is obtained inthe usual manner by incorporating the active substance, if desired, in asolvent, in a volatile liquid to be used as a propellant, for example, amixture of chlorine-fluorine derivatives of methane and ethane, amixture of lower hydrocarbons, dimethyl ether, or gases such as carbondioxide, nitrogen, and nitrous oxide.

Fumigating candles or fumigating powders, i.e., compositions which,while burning, can generate a pesticidal smoke, are obtained by takingup the active substance in a combustible mixture which may contain as afuel a sugar or a wood, preferably in a ground form, a substance tomaintain combustion, for example, ammonium nitrate or potassiumchlorate, and, furthermore, a substance to delay combustion, forexample, kaolin, bentonite and/or colloidal silicic acid.

In addition to the above-mentioned ingredients, the agents according tothe invention may also contain other substances known for use in thistype of agents. For example, a lubricant, for example, calcium stearateor magnesium stearate, may be added to a dispersible powder or a mixtureto be granulated. "Adhesives," for example, polyvinylalcohol cellulosederivatives or other colloidal materials, such as casein, may also beadded so as to improve the adhesion of the pesticide to the crop.Furthermore, a substance may be added to reduce the phytotoxicity of theactive substance, carrier material or auxiliary substance, for example,wool fat or wool fatty alcohol.

Pesticidal compounds known per se may also be incorporated in thecompositions according to the present invention. As a result of this,the activity spectrum of the composition is widened and synergism mayoccur.

For use in such a combination composition are to be considered thefollowing known insecticidal, acaricidal and fungicidal compounds.

Insecticides, for example:

1. organic chlorine compounds, for example,6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzo[e]-dioxathiepine-3-oxide;

2. carbamates, for example, 2-dimethylamino-5,6-dimethylpyrimidin-4-yldimethyl carbamate and 2-isopropoxyphenylmethylcarbamate;

3. di(m)ethylphosphates, for example,2-chloro-2-diethylcarbamoyl-1-methylvinyl--,2-methoxycarbonyl-1-methylvinyl--,2-chloro-1-(2,4-dichlorophenyl)vinyl--, and2-chloro-1-(2,4,5-trichlorophenyl)vinyl di(m)ethyl phosphate;

4. 0,0-di(m)ethyl phosphorothioates, for example,0(S)-2-methylthioethyl--, S-2-ethylsulphinylethyl--,S-2-(1-methylcarbamoylethylthio)ethyl--, 0-4-bromo-2,5-dichlorophenyl--,0-3,5,6-trichloro-2-pyridyl--, 0-2-isopropyl-6-methylpyrimidin-4-yl--,and 0-4-nitrophenyl 0,0-di(m)ethyl phosphorothioate;

5. 0,0-di(m)ethyl phosphorodithioates, for example,S-methylcarbamoylmethyl--, S-2-ethylthioethyl--,S-(3,4-dihydro-4-oxobenzo [d]-1,2,3-triazin-3-ylmethyl--,S-1,2-di(ethoxycarbonyl)ethyl--,S-6-chloro-2-oxobenzoxazolin-3-ylmethyl--, andS-2,3-dihydro-5-methoxy-2-oxo-1,3,4-thiadiazol-3-yl-methyl0,0-di(m)ethyl phosphorodithioate;

6. phosphonates, for example, dimethyl2,2,2-trichloro-1-hydroxyethylphosphonate;

7. benzoylurea, for example,N-(2,6-difluorobenzoyl)-N'-(4-chlorophenyl)urea;

8. natural and synthetic pyrethroids;

9. amidines, for example,N'-(2-methyl-4-chlorophenyl)-N,N-dimethylformamidine; and

10. microbial insecticides, such as Bacillus thuringiensis.

Acaricides, for example:

1. organic tin compounds, for example, tricyclohexyl tin hydroxide anddi[tri-(2-methyl-2-phenylpropyl)tin]oxide;

2. organic halogen compounds, for example, isopropyl4,4'-dibromobenzilate, 2,2,2-trichloro-1,1-di(4-chlorophenyl)ethanol and2,4,5,4'-tetrachlorodiphenyl sulphone; and, furthermore:3-chloro-α-ethoxyimino-2,6-dimethoxybenzyl benzoate and 0,0-dimethylS-methylcarbamoyl methyl phosphorothioate.

Fungicides, for example:

1. organic tin compounds, for example, triphenyl tin hydroxide andtriphenyl tin acetate;

2. alkylene bisdithiocarbamates, for example, zincethylenebisdithiocarbamate and manganese ethylene bisdithiocarbamate;

3. 1-acyl or 1-carbomoyl-N-benzimidazole (-2) carbamates and 1,2-bis(3-alkoxycarbonyl-2-thiureido)benzene, and furthermore,2,4-dinitro-6-(2-octylphenylcrotonate), 1-[bis(dimethylamino)phosphoryl]-3-phenyl-5-amino-1,2,4-triazole,N-trichloromethylthiophthalimide,N-trichloromethylthiotetrahydrophthalimide,N-(1,1,2,2-tetrachloroethylthio)-tetrahydrophthalimide,N-dichlorofluoromethylthio-N-phenyl-N,N'-dimethylsulphamide,tetrachloroisophthalonitrile, 2-(4'-thiazolyl)-benzimidazole,5-butyl-2-ethylamino-6-methylpyrimidine-4-yl-dimethylsulphamate,1-(4-chlorophenoxy)-3,3-dimethyl-1(1,2,4-triazole-1-yl)-2-butanone,α-(2-chlorophenyl)-α-(4-chlorophenyl)-5-pyrimidinemethanol,1-(isopropylcarbamoyl)-3-(3,5-dichlorophenyl) hydantoin,N-(1,1,2,2-tetrachloroethylthio)-4-cyclohexene-1,2-carboximide,N-trichloromethylmercapto-4-cyclohexene-1,2-dicarboximide,N-tridecyl-2,6-dimethylmorpholine, and5,6-dihydro-2-methyl-1,4-oxathiine-3-carboxanilide.

The dosages of the composition according to the invention desired forpractical application will, of course, depend on various factors, forexample, field of application, selected active substance, form ofcomposition, nature and extent of the infection, and the weatherconditions. In general, favorable results are achieved with a dosagewhich corresponds to 250 to 1000 g of the active substance per hectare.When applied against phytophagous microorganisms good results areachieved when the soil is treated with a composition comprising anamount of active compound which corresponds to 2 to 100 kg of activesubstance per ha. When applied to the seed itself a dosage is preferredwhich corresponds to 100 to 1500 mg of active substance per kg of seed.

The compounds according to the invention are new compounds which can beprepared in a manner known per se for the synthesis of relatedcompounds. For example, the new compounds of the general formula##STR4## wherein R, R₁ and R₂ have the above meanings, and

p is 1 or 2,

can be prepared by reacting a compound of the general formula ##STR5##with an oxidizing agent. Suitable oxidizing agents are hydrogen peroxideand peroxycarboxylic acids, for example, peracetic acid, or asubstituted perbenzoic acid such as p-nitroperbenzoic acid orm-chloroperbenzoic acid. For the preparation of the sulphone, hydrogenperoxide is preferably used as an oxidizing agent. When peroxycarboxylicacids, for example, p-nitroperbenzoic acid or m-chloroperbenzoic acid,are used, the sulphide is oxidized selectively to the sulphoxide. Theseoxidation reactions are preferably carried out in a polar organicsolvent, for example, acetic acid, an alcohol such as methanol, or achlorinated hydrocarbon, for example, chloroform. The reactiontemperature depends on the reagents used and the selected solvent, andmay vary between 0° C. and the boiling point of the solvent. Afterisolating the final product, it may be purified, if desired, byrecrystallization.

The above thiocompounds of the general formula ##STR6## can be preparedby converting the corresponding 2-halogen compound with a suitablealkali mercaptide. The reaction is carried out in an inert polar organicsolvent, e.g., an alcohol such as ethanol, at a reaction temperaturebetween 0° C. and the boiling point of the solvent.

2-(substituted)alkylthio-3-nitrothiophenes can also be preparedaccording to a method described by Henriksen and Autrup in Acta Chem.Scand. 24 (1970), 2629-2633. According to this method, a2-nitroethylene-1,1-dithiolate is reacted with an α-halogen aldehyde orketone, succeeded by ring closure and reaction with a suitable(substituted) alkylhalogenide.

When in the above formula R₂ is an alkoxycarboximidoyl group, thisthiocompound can be prepared by reacting the corresponding2-halo-3-nitro-5-cyanothiophene with an alkalimercaptide in the presenceof a suitable alcohol.

Thiocompounds of the above general formula, in which R₂ is a cyanogroup, can be prepared in a manner known per se for the synthesis ofrelated compounds, for example, by reacting the corresponding2-thio-3-nitro-5-formyl-thiophene, preferably in sodium formiate-formicacid, with hydroxyl amine; the 2-thio-3-nitro-5-formyl-thiophenecompound can be prepared by converting the corresponding halogencompound with a suitable alkalimercaptide.

The invention will now be described in greater detail with reference tothe following specific examples.

EXAMPLE I Preparation of 2-methylsulphinyl-3-nitrothiophene

There was added 0.95 g of p-nitroperbenzoic acid to a solution of 0.88 gof 2-methylthio-3-nitrothiophene in 15 ml of chloroform at a temperaturefrom 0° to 10° C. After stirring for 2 hours at 5° C., a solution of 2 gof sodium bicarbonate in approximately 50 ml of water was added; thereaction mixture was then stirred for 15 minutes. The chloroform layerwas separated, washed with water, and filtered. After distilling thesolvent, the desired product was obtained in a yield of 0.95 g;melting-point 155° C.

The following compounds were prepared in a corresponding manner inwhich, if desired, m-chloroperbenzoic acid was used as an oxidizingagent and methanol as a solvent.

2-methylsulphinyl-3-nitro-4-methylthiophene, m.p. 142° C.;

2-methylsulphinyl-3-nitro-5-ethoxycarboximidoyl thiophene, m.p. 210° C.;

2-methylsulphinyl-3-nitro-5-cyanothiophene, m.p. 160° C.;

2-methylsulphinyl-3-nitro-4,5-dimethylthiophene, m.p. 156° C.;

2-(4-chlorophenylsulphinyl)-3-nitrothiophene, m.p. 163°-165° C.;

2-phenylsulphinyl-3-nitrothiophene, m.p. 124°-126° C.;

2-(4-methoxyphenylsulphinyl)-3-nitrothiophene, m.p. 156°-157° C.;

2-methylsulphinyl-3-nitro-5-ethoxycarbonylthiophene, m.p. 95°-99° C.;

2-ethylsulphinyl-3-nitrothiophene, m.p. 79°-82° C.;

2-n-propylsulphinyl-3-nitrothiophene, m.p. 81°-84° C.;

2-isobutylsulphinyl-3-nitrothiophene, m.p. 91°-93° C.;

2-methylsulphinyl-3-nitro-5-acetylthiophene, m.p. 161°-163° C.;

2-[3-nitrothienyl(-2)sulphinyl]pyridine-N-oxide, m.p. 174° C. (decomp.);

2-(4-nitrophenylsulphinyl)-3-nitrothiophene, m.p. 194°-196° C.;

2-methylsulphinyl-3-nitro-4-phenylthiophene, m.p. 171°-173° C.;

2-n-heptylsulphinyl-3-nitrothiophene, m.p. 68°-71° C.;

2-ethoxycarbonylmethylsulphinyl-3-nitrothiophene, m.p. 52°-54° C.;

2-[3-nitro-5-cyanothienyl(-2)sulphinyl]pyridine-N-oxide, m.p. 158° C.(decomp.);

2-phenylsulphinyl-3-nitro-5-cyanothiophene, m.p. 158°-160° C.;

2-[3-nitrothienyl(-2)sulphinyl]-3-nitropyridine, m.p. 181°-183° C.(decomp.);

2-methylsulphinyl-3-nitro-4-chlorothiophene, m.p. 114°-116° C.;

2-thiocyanatomethylsulphinyl-3-nitrothiophene, m.p. 138°-140° C.;

2-methylsulphinyl-3-nitro-5-N,N-dimethylaminosulphonylthiophene, m.p.153°-154° C.;

2-ethylsulphinyl-3-nitro-5-acetylthiophene, m.p. 146° C. (decomp.);

2-methylsulphinyl-3-nitro-5-hydroxymethylthiophene, m.p. 112.5°-113.5°C.;

2-methylsulphinyl-3-nitro-5-(1-hydroxyethyl)thiophene, m.p.118.5°-120.5° C.;

2-methylsulphinyl-3-nitro-5-ethylenedioxymethylthiophene, m.p.125°-126.5° C.; and

2-methylsulphinyl-3-nitro-5-bromomethylthiophene, m.p. 138°-139° C.

EXAMPLE II Preparation of 2-methylsulphonyl-3-nitrothiophene

There was added 1.25 ml of a 33% solution of hydrogen peroxide in waterto a solution of 0.88 g of 2-methylthio-3-nitrothiophene in 10 ml ofacetic acid at approximately 100° C. After heating at approximately 100°C. for approximately 30 minutes, another 1.25 ml of the same hydrogenperoxide solution were added. After heating at approximately 100° C. for3 hours, the reaction mixture was cooled and poured in water. Theprecipitate of 2-methylsulphonyl-3-nitrothiophene was sucked off anddried; weight 0.85; g; melting-point 121° C.

In a corresponding manner, the following compounds were prepared:

2-methylsulphonyl-3-nitro-4-methylthiophene, m.p. 130° C.;

2-methylsulphonyl-3-nitro-4-phenylthiophene, m.p. 119°-120° C.;

2-ethylsulphonyl-3-nitrothiophene, m.p. 84°-86° C.;

2-n-propylsulphonyl-3-nitrothiophene, m.p. 49°-52° C.;

2-methylsulphonyl-3-nitro-5-cyanothiophene, m.p. 175°-177° C.;

2-ethoxycarbonylmethylsulphonyl-3-nitrothiophene, m.p. 96°-98° C.;

2-phenylsulphonyl-3-nitro-5-cyanothiophene, m.p. 178°-180° C.;

2-methylsulphonyl-3-nitro-5-acetylthiophene, m.p. 160°-161° C.;

2-thiocyanatomethylsulphonyl-3-nitrothiophene, m.p. 144°-147° C.;

2-methylsulphonyl-3-nitro-5-N,N-dimethylaminosulphonylthiophene, m.p.175°-176° C.;

2-ethylsulphonyl-3-nitro-5-acetylthiophene, m.p. 137.5°-138.5° C.;

2-methylsulphonyl-3-nitro-5-hydroxymethylthiophene, m.p. 101.5°-102.5°C.;

2-methylsulphonyl-3-nitro-5-(1-hydroxyethyl)thiophene, m.p. 91°-92° C.;and

2-methylsulphonyl-3-nitro-5-ethylenedioxymethylthiophene, m.p. 142°-143°C.

EXAMPLE III Preparation of methylthio-3-nitro-5-acetylthiophene

Liquid methylmercaptan (4 ml) was added to a solution of 0.82 g of Na in50 ml of absolute ethanol. The resulting solution was added to asolution of 7.2 g of 2-chloro-3-nitro-5-acetylthiophene in 200 ml ofabsolute ethanol in 15 minutes at 5° C. After stirring at roomtemperature for 30 minutes, 100 ml of water was added, after which theprecipitate was sucked off and washed successively with water andisopropanol. The precipitate was boiled a moment with 300 ml ofcarbontetrachloride, cooled down, and sucked off. After drying the titlecompound was obtained in a yield of 6.4 g; m.p. 191°-193° C.

In a corresponding manner the following compound was prepared:

2-[3-nitro-5-formylthienyl(-2)thio]pyridine-N-oxide, m.p. 165° C.(decomp.).

EXAMPLE IV Preparation of 2-thiocyanomethylthio-3-nitrothiophene

A solution of 12.8 ml of monochloroacetaldehyde in 12.8 ml of water wasadded to a solution of 35.0 g dipotassium 2-nitroethylene-1,1-dithiolatein 225 ml of water, while stirring at room temperature. The reactionmixture was cooled down to 0° C., after which successively 16 ml ofconcentrated hydrochloric acid and 16 ml of concentrated potassiumhydroxide were added, both for 5 minutes; after each addition thereaction mixture was stirred for 5 minutes. Thereafter 13 ml ofchloromethylthiocyanate was added in 5 minutes. The reaction mixture wasstirred at room temperature during 1.5 hour, and was left to standovernight. Dichloromethane was added and the reaction mixture wasstirred at room temperature during 0.5 hour. After sucking off solidmaterial, the dichloromethane layer was separated and washed with water.The solvent was evaporated and the product was obtained by purificationvia column chromatography. The desired product was obtained in a yieldof 7.1 g; m.p. 86°-87° C.

In a corresponding manner the following compounds were prepared:

2-ethylthio-3-nitrothiophene, m.p. 51°-53° C.; and

2-methylthio-3-nitro-4-methylthiophene, m.p. 104° C.

EXAMPLE V Preparation of 2-methylthio-3-nitro-5-cyanothiophene

A sodium methyl mercaptide solution was prepared by adding 5 ml ofmethylmercaptan to 1.75 g of Na in 60 ml of absolute ethanol. Whilestirring and cooling this solution to below 10° C. it was added to asolution of 17.6 g of 2-bromo-3-nitro-5-formylthiophene in 200 ml ofethanol. After stirring at room temperature for another 2 hours, 200 mlof water were added, after which the formed precipitate was sucked off,washed with water-ethanol mixture (1:1 v/v), and recrystallized fromisopropanol. 6.5 g of 2-methylthio-3-nitro-5-formylthiophene of meltingpoint 129°-131° C. were obtained. Then 2.35 g of NaHCO₃, 3.1 g of2-methylthio-3-nitro-5-formylthiophene, and 1.2 g of NH₂ OH.HCl wereadded successively to 50 ml of formic acid. The reaction mixture wasrefluxed for 1 hour, after which, water was added and the formedprecipitate was sucked off. After recrystallization from isopropanol thedesired 2-methylthio-3-nitro-5-cyanthiophene was obtained in a yield of2.3 g; melting point 150° C.

EXAMPLE VI Test on activity against Pythium spp. and Rhizoctonia solani;soil treatment

Compositions of the compounds to be tested were prepared by suspending15 ml of the active substances in 20 ml of water; 1 kg of soil infectedwith Pythium spp. and Rhizoctonia solani was mixed with thiscomposition. Because Pythium spp. and Rhizoctonia solani developexcellently in the soil on corn grains and flax stalks, respectively,corn grains and flax stalks were added to the soil ("trapping"). After 4days at 20° C. in the glass-house, the corn grains and the flax stalkswere rinsed with tap water and laid on an artificial culture mediumwhich consisted to 2% Bacto agar in water. After an incubation period of24 hours at 23° C. it was tested whether, and if so to what extent, thefungi had developed. Table A shows this development. When thedevelopment has been flourishing, this is denoted by "-." A partialdevelopment is denoted by "±". When the fungi on the culture medium havenot developed, the active substance has had a good activity; this isdenoted by "+" in the Table. The compound numbers refer to thecorresponding compounds listed previously in the specification.

                  TABLE A                                                         ______________________________________                                                      Dosage in mg/kg                                                                            Development of                                     Compound no.  of soil      the fungi                                          ______________________________________                                        (1)           15           +                                                  (2)           15           +                                                  (9)           15           +                                                  (10)          15           +                                                  (11)          15           +                                                  (13)          15           ±                                               2-methylsulphinyl-4-                                                                        15           -                                                  methyl-5-nitrothiazole                                                        (known)                                                                       control       --           -                                                  ______________________________________                                    

EXAMPLE VII Test with respect to the protection of seedlings against aplant pathogenic soil fungus, namely, Pythium spp., by means of a seedtreatment

The compounds to be tested were processed to compositions by pulverizingthem and then mixing them in the desired concentration (see Table B)with kaolin.

Beet seed was treated with these compositions in a quantity of 6 g ofcomposition per kg of seed and then sowed in trays containing soil whichwas badly infected with Pythium spp. After 3 weeks in a glass-house at18°-22° C. and a relative humidity of 70-100%, the percentage of come-upand healthy seedlings was determined. The results are recorded in TableB.

                  TABLE B                                                         ______________________________________                                                      Dosage in mg of                                                                           Percentage                                                        active substance                                                                          come-up and                                         Compound no.  per kg of seed                                                                            healthy plants                                      ______________________________________                                         (1)          1500        100                                                               600         95                                                   (2)          1500        80                                                                600         62                                                  (13)          1500        95                                                                600         40                                                  (10)          1500        98                                                                600         75                                                   (9)          1500        97                                                                600         70                                                  (17)          1500        45                                                                600         30                                                  (16)          1500        50                                                                600         35                                                  (14)          1500        75                                                                600         30                                                  (15)          1500        80                                                                600         42                                                  (11)          1500        98                                                                600         75                                                  (12)          1500        80                                                                600         65                                                  (40)          1500        100                                                               600         95                                                  (43)          1500        100                                                               600         95                                                  control (kaolin)                                                                            --           5                                                  ______________________________________                                    

EXAMPLE VIII Test with respect to the protection of seedling against aplant pathogenic seed fungus, namely, Fusarium nivale, by means of aseed treatment

Wheat seed, infected with Fusarium nivale, was treated with 3 g of acomposition obtained according to Example VII per kg of seed and wasthen sowed in trays containing soil. These trays were placed in aWisconsin tank having a soil temperature of 8°-12° C. After 3 weeks thenumber of come-up and healthy plants was determined. The come-up ofplants from untreated seed served for control and has arbitrarily beenfixed at 100. The results are recorded in Table C.

                  TABLE C                                                         ______________________________________                                                      Dosage in mg of                                                                           Percentage of                                                     active substance                                                                          come-up and                                         Compound no.  per kg of seed                                                                            healthy plants                                      ______________________________________                                        (1)           750         148                                                               600         143                                                               300         137                                                 (11)          750         145                                                               300         130                                                 (2)           600         128                                                               300         124                                                 (13)          600         134                                                               300         120                                                 (9)           600         135                                                               300         113                                                 (8)           600         134                                                               300         106                                                 control       --          100                                                 ______________________________________                                    

EXAMPLE IX Field experiments with respect to the protection of seedlingsagainst various plant pathogenic seed fungi by means of a seed treatment

Wheat seed, infected with Tilletia caries, barley seed, infected withPyrenophora graminea and Ustilago nuda, respectively, and oats seed,infected with Ustilago avenae, were treated with 3 g of a compositionobtained according to Example VII per kg of seeds. The seeds were thensowed in the field in tracks of two running meters. Each experiment wascarried out in quintuplicate. After the spike formation, the number ofsick plants was determined with reference to spike symtoms. The resultsrecorded in Table D were obtained.

                  TABLE D                                                         ______________________________________                                                Dosage in mg of                                                                          Percentage of diseased plants                                        active substance                                                                           Wheat/   Barley/                                                                              Oats/                                  Compound no.                                                                            per kg of seeds                                                                            T. ca.   P. gra.                                                                              U. av.                                 ______________________________________                                        (1)       1200         0.0      0.0    1.9                                              600          1.2      2.4    5.1                                              300          2.2      8.2    9.4                                    (2)       1200         0.0             7.0                                              600          0.2             7.5                                    (13)      1200         0.2             7.8                                              600          1.4             7.5                                    control   --           24.4     24.2   27.2                                   ______________________________________                                    

In the same way a second series of field experiments was carried out.The results are presented in Table E. In the last three columns thepercentage of diseased plants is shown in comparison with that fromuntreated seed. The percentage of diseased plants from untreated seedhas arbitrarily been fixed at 100.

                  TABLE E                                                         ______________________________________                                                Dosage in mg of                                                                          Percentage of diseased plants                                        active substance                                                                           Wheat/   Barley/                                                                              Oats/                                  Compound no.                                                                            per kg of seeds                                                                            T. ca.   P. gra.                                                                              U. av.                                 ______________________________________                                        (1)       300          44       14      9                                               600          18       3       8                                               900          24       8       5                                     (2)       300          20       23     52                                               600          18       12     13                                               900          10       16     15                                     (13)      300          60       13     31                                               600          51       17     28                                               900          13       5      16                                     (3)       300          55       15     19                                               600          15       6       5                                               900          18       6       7                                     (6)       300          81       5      89                                               600          65       2      73                                               900          69       2      41                                     (4)       300          97       20     88                                               600          53       14     51                                               900          45       3      36                                     (5)       300          91       15     60                                               600          78       3      29                                               900          35       2      21                                     control   --           100      100    100                                    ______________________________________                                    

EXAMPLE X Test on activity against leaf fungi

The compounds to be tested were processed to compositions by dispersingthe compounds in water by means of a dispersing agent, for example,lignin sulphonate, and/or a wetting agent, for example, naphthalenesulphonate, an alkylbenzene sulphonate, an alkyl polyoxyethylene or analkylaryl polyoxyethylene. The crop to be protected against false mildewon tomato (Phytophthora infestans) was treated with these compositionsby spraying young tomato plants, approximately 10 cm high, with theabove suspensions of the active substances in the concentrationindicated in Table F below. The plants thus treated were then infectedwith Phytophthora infestans by spraying the plants with an aqueoussuspension containing per ml 100,000 spores of Phytophthora infestans.After an incubation period of 4 days at a temperature of 18° C. and arelative humidity of 100%, it was determined to what extent the fungihad developed. During the incubation period, a light-dark cycle of 16/8hours had been used.

The results of the treatment are recorded in Table F. In this Table, theconcentration of the compound used is indicated in mg of activesubstance per liter and the protection against Phytophthora infestanswhich was found with this concentration: 100% means total protection, 0%means no protection.

In the same manner as described above, young dwarf French beans,approximately 10 cm high, were treated against rust of beans (Uromycesphaseoli). Infecting the plants was done with an aqueous suspensioncontaning 300,000 spores of Uromyces phaseoil per ml. The incubationperiod was 10 days at a temperature of 18° C. and a relative humidity of100%. The results obtained are also recorded in Table F.

                  TABLE F                                                         ______________________________________                                                 Concentration in                                                                           % Protection                                                       mg of active sub-                                                                            bean/   tomato/                                     Compound no.                                                                             stance per liter                                                                             U. pha. P. inf.                                     ______________________________________                                        (1)        300            100     100                                         (2)        300            100     70                                          (13)       300            100     55                                          (11)       300            100     100                                         (12)       300            100     70                                          2-methylsulphinyl-                                                                       300             0       0                                          4-methyl-5-nitro-                                                             thiazole (known)                                                              control    --              0       0                                          ______________________________________                                    

EXAMPLE XI In vitro test on activity against phytophagous microorganisms

The compounds to be tested were incorporated into a culture medium,consisting of 1% by weight of glucose, 0.2% by weight of a yeast extract(marmite), 0.5% by weight of a protein (pepton), 2.5% by weight ofagar-agar and 95.8% by weight of distilled water, in Petri dishes inconcentrations of 10, 30, and 100 ppm. The Petri dishes were inoculatedwith the plantpathogenic fungi Fusarium nivale, Rhizoctonia solani andPythium ultimum and the plantpathogenic bacterium Erwinia carotovora,and then kept at a temperature of 20° C. After 48 hours, the growthinhibiting activity of the compounds was determined visually; theresults are recorded in Table G.

                                      TABLE G                                     __________________________________________________________________________            Concentration                                                                         % inhibition of the growth of the fungus/bacterium            Compound no.                                                                          in ppm  Fusarium niv.                                                                        Rhizoct. sol.                                                                        Pyth. ult.                                                                         Erw. car.                                  __________________________________________________________________________     (1)    10      65     30     100  100                                                30      100    50     100  100                                                100     100    100    100  100                                         (2)    10      65     15     100  50                                                 30      100    60     100  100                                                100     100    85     100  100                                        (13)    10      0      20     60   0                                                  30      45     55     100  0                                                  100     100    65     100  100                                        (10)    10      20     40     45   100                                                30      55     55     75   100                                                100     100    60     100  100                                         (9)    10      0      5      25   0                                                  30      50     50     25   100                                                100     85     65     90   100                                         (8)    10      10     15     25   0                                                  30      85     55     80   100                                                100     100    75     100  100                                        (19)    10      65     10     100  0                                                  30      100    50     100  0                                                  100     100    65     100  50                                          (7)    10      65     30     75   50                                                 30      100    40     100  100                                                100     100    100    100  100                                        (32)    10      10     40     65   100                                                30      35     65     100  100                                                100     100    65     100  100                                        (15)    10      70     5      55   50                                                 30      100    35     90   100                                                100     100    70     100  100                                        (27)    10      15     15     0    100                                                30      100    35     80   100                                                100     100    50     100  100                                        (28)    10      0      20     40   0                                                  30      25     55     60   50                                                 100     65     60     100  100                                         (3)    10      65     30     100  50                                                 30      100    70     100  100                                                100     100    100    100  100                                         (4)    10      65     15     80   50                                                 30      100    70     100  50                                                 100     100    85     100  100                                         (5)    10      70     25     80   0                                                  30      100    60     100  0                                                  100     100    85     100  50                                         (23)    10      60     60     80   0                                                  30      70     80     100  0                                                  100     70     85     100  0                                          (26)    10      45     20     40   0                                                  20      50     50     85   50                                                 100     100    65     100  100                                        (18)    10      55     50     45   50                                                 30      100    65     100  100                                                100     70x    35x    30x  50x                                        (34)    10      25     15     35   50                                                 30      50     40     85   100                                                100     100    60     100  100                                        (30)    10      20     15     45   100                                                30      55     30     75   100                                                100     100    70     100  100                                        (11)    10      35     30     35   50                                                 30      80     50     90   100                                                100     100    65     100  100                                        (12)    10      0      35     50   0                                                  30      35     45     100  0                                                  100     35     70     100  0                                          (31)    10      0      30     50   100                                                30      80     65     65   100                                                100     45x    65x    100x 100x                                       (33)    10      0      0      15   100                                                30      35     10     40   100                                                100     45     60     75   100                                        (20)    10      35     45     20   0                                                  30      55     55     30   50                                                 100     45x    50x    30x  50x                                        (21)    10      35     15     20   0                                                  30      35     25     70   50                                                 100     100    50     100  100                                        (22)    10      35     15     0    0                                                  30      95     50     50   50                                                 100     100    60     100  100                                        (24)    10      25     35     0    50                                                 30      50     55     55   100                                                100     90     60     100  100                                        (25)    10      20     25     0    50                                                 30      65     25     30   50                                                 100     90     40     100  100                                        (29)    10      25     40     15   50                                                 30      35x    40x    25x  100x                                               100     50x    55x    40x  100x                                       (37)    10      15     50     0    0                                                  30      55     85     65   0                                                  100     55x    55x    75x  0x                                         (6)     10      85     20     75   100                                                30      100    65     100  100                                                100     100    100    100  100                                        (35)    10      0      35     75   0                                                  30      100    35     100  100                                                100     100    35     100  100                                        (36)    10      0      45     0    0                                                  30      45     80     50   0                                                  100     100    85     100  0                                          (38)    10      15            31                                                      30      47            31                                                      100     52            100                                             (39)    10      28            56                                                      30      42            56                                                      100     61            80                                              (40)    10      64            42                                                      30      71            82                                                      100     100           100                                             (41)    10      59            43                                                      30      64            46                                                      100     100           91                                              (42)    10      30            70                                                      30      20            67                                                      100     100           100                                             (43)    10      23            52                                                      30      25            46                                                      100     64            77                                              (44)    10      30            70                                                      30      30            85                                                      100     100           100                                             (45)    10      8             45                                                      30      8             45                                                      100     57            91                                              (46)    10      71            45                                                      30      66            74                                                      100     100           100                                             (47)    10      25            50                                                      30      49            60                                                      100     100           100                                             (48)    10      76            62                                                      30      78            84                                                      100     100           100                                             control --      0      0      0    0                                          __________________________________________________________________________     x Note:                                                                       crystallization of active compound.                                      

What we claim is:
 1. A compound of the formula ##STR7## wherein R' is C₁-C₄ alkyl,R₁ ' is a hydrogen atom or C₁ -C₄ alkyl, and R₂ ' is ahydrogen atom or an acetyl group.
 2. 2-Methylsulphinyl-3-nitrothiophene.3. 2-Methylsulphinyl-3-nitro-4-methylthiophene. 4.2-Ethylsulphinyl-3-nitrothiophene. 5.2-Methylsulphinyl-3-nitro-5-acetylthiophene. 6.2-Ethylsulphinyl-3-nitro-5-acetylthiophene.